1. Field of the Invention
The present invention relates to a cooling apparatus having a cooling mechanism for cooling a heat sink in a thermal analyzer or the like, and to a thermal analyzer, such as a differential scanning calorimeter, equipped with the cooling apparatus.
2. Description of the Related Art
A thermal analyzer such as differential scanning calorimeter includes a heat sink which is under a temperature control, a specimen disposed in the inside of the heat sink, a reference material holder, a heater which heats the heat sink, and a cooling device which cools the heat sink. As such a cooling device, conventionally, there have been known a gas cooling device which performs cooling using a low-temperature gas which is obtained by evaporating liquefied nitrogen or the like (see, for example, Japanese Accepted Patent Publication Hei7(1995)-122619(fourth column, FIG. 1), Japanese Accepted Patent Publication Hei7(1995)-65974(fourth column, FIG. 1)), and an electric cooling device which incorporates a compressor therein and performs cooling by way of a metal-made cooling member which is cooled by a refrigerant cooled by the compressor. Cooling has been conventionally performed by mounting either one of a cooling members of these gas cooling device and the electric cooling device on a furnace of the thermal analyzer in an exchangeable manner depending on the necessity.
In the conventional differential scanning calorimeter, only one type of cooling device can be mounted on the differential scanning calorimeter and, therefore, it is possible to use only one type of cooling method. Accordingly, when the gas cooling device is used, although cooling can be performed up to −150° C., there have been drawbacks in that it is necessary to replenish liquefied nitrogen which is a refrigerant and, at the same time, when the heat sink is cooled rapidly, the amount of gas consumed is increased.
Further, when the electric cooling device is used, since a refrigerant is hermetically sealed, it is unnecessary to replenish the refrigerant. However, with respect to the inexpensive electric cooling device which exhibits the favorable operability, there has been a drawback in that the cooling of −100° C. or below cannot be performed due to a capacity thereof.
Further, it has been considered cumbersome to exchange a cooling head which covers the heat sink between the cooling head for the electric cooling device and the gas cooling device depending on the use thereof.